Bioengineering and Imaging Research Opportunities Workshop V: A Summary

The fifth Bioengineering and Imaging Research Opportunities Workshop (BIROW V) was held on January 18–19, 2008. As with previous BIROW meetings, the purpose of BIROW V was to identify and characterize research and engineering opportunities in biomedical engineering and imaging. The topic of this BIROW meeting was Imaging and Characterizing Structure and Function in Native and Engineered Tissues. Under this topic, four areas were explored in depth: (1) Heterogeneous single-cell measurements and their integration into tissue and organism models; (2) Functional, molecular, and structural imaging of engineered tissue in vitro and in vivo; (3) New technologies for characterizing cells and tissues in situ; (4) Imaging for targeted cell, gene, and drug delivery.     

慢病毒载体介导的转基因整合位点研究方法

慢病毒载体整合到宿主细胞的染色体上可以长期稳定表达,目前已成为基因治疗和转基因动物载体研究的热点.慢病毒载体整合的位置效应是影响外源基因表达的重要因素,慢病毒载体整合位点的研究是探索外源基因整合机制的手段之一.转基因整合位点研究的方法主要有5种:荧光原位杂交、个体基因组文库筛选法、反向PCR、接头PCR、锚定PCR.近来的研究后发现整合位点之间可能存在一些共同特征.     

Placental pathology for the surgical pathologist

Pathologic examination of the placenta is of clinical importance in the evaluation of pregnancies with a less than perfect outcome. Morphologic alterations of the placenta can mirror disorders of the fetus and the mother and evaluation of the placenta can identify clinically significant lesions, allow understanding of a child's disability and may have a role in resolving medical-legal disputes. Pathologic findings in the placenta can provide information on the pathogenesis of cerebral palsy, mental retardation, or neurodevelopmental disorders. This review will cover a variety of frequently encountered, clinically important, and morphologically distinct disorders of the placenta. The current understanding of the clinical implications of lesions for the mother, infant, and for future pregnancies will also be considered.     

植入式人体通信技术的耦合方式研究

研究植入式人体通信方式中通信信号的衰减与不同耦合方式之间的关系。涉及的耦合方式包括电容耦合、电流耦合、正向容阻耦合和反向容阻耦合4种。通过建立等效电路模型进行仿真计算,以及在模拟体内环境的水模型中实验测量的方式,对20 MHz通信频率下不同耦合方式的通信衰减进行对比。仿真和实验的结果均表明,正向容阻耦合方式下通信的衰减最小,分别为26 dB(计算值)和28 dB(测量值),而电容耦合、电流耦合和反向容阻耦合方式的通信衰减依次增大。这一结果反映出不同耦合方式之间的机制区别,同时意味着若将人体通信方式应用于植入式医疗设备中,正向容阻耦合方式将是最好的选择。     

Placental pathology

The placenta is a unique organ, given that it resides at the interface between two human beings – the mother and the fetus. Additionally, it changes throughout gestation in such a dynamic way that identifying the normal histology can be a challenge in and of itself. This article summarizes the most common pathologic changes in the placenta, devoting the greatest amount of information to the inflammatory disorders and abnormalities of fetal and maternal perfusion. These include acute chorioamnionitis and funisitis/chorionic plate vasculitis, chronic villitis, and changes secondary to maternal vasculopathy and fetal thrombosis. Less common abnormalities that are either often seen or important to identify are described, and the findings in the most common perinatal infections are summarized. Finally, the clinical associations of the placental pathologic findings are described. The intent is to provide a framework for diagnosing common placental abnormalities, and references are provided for further reading.     

Placental immunoregulation

Mammalian gestation is complex and varies widely among species, but the embryonic contribution to the maternal-fetal interface, the trophoblast, remains constant. Alloantigen and stage/tissue specific antigens are present on the trophoblast in low concentration and often in locations inaccessible to maternal immune effectors. Nonetheless, pregnancy does prime the mother for humoral immunity; cell-mediated responses are more difficult to demonstrate. The placenta appears to be an efficient block to cellular traffic into the fetus; the placental barrier to specific antibody has been established, but its efficiency is controversial. Nonspecific, local, active suppression mediated by lymphoid cells within the decidua is apparently an important concomitant of successful gestation. Yet there is evidence that an ongoing immune response is beneficial to pregnancy, allowing an increase in placental size in response to growth-promoting lymphokines while blocking graft-rejection mechanisms. Thus it appears that immunoregulation at the maternal-fetal interface is complex, and no single mechanism can account for the success of the "fetal allograft".